Dark matter map to reveal universe's secrets

Surveying how dark matter is distributed and how the distribution changes over time is essential to understanding the role of dark energy that controls the expansion of the universe, feel researchers. As a consequence, researchers from the National Astronomical Observatory of Japan (NAOJ), the University of Tokyo and other institutions have begun a wide-area survey of the distribution of dark matter in the universe using Hyper Suprime-Cam, a new wide-field camera installed on the Subaru Telescope in Hawai.

"Now we know we have them both, a technique and a tool for understanding dark energy. We are ready to use Hyper Suprime-Cam to create a 1000 square degree dark matter map that will reveal the expansion history of the universe with precise detail," said research leader Satoshi Miyazaki from the NAOJ.

Initial results from observations covering an area of 2.3 square degrees on the sky toward the constellation Cancer revealed nine large concentrations of dark matter, each the mass of a galaxy cluster.

These first results demonstrate that astronomers now have the techniques and tools to understand dark energy.

The next step is to expand the survey to cover a thousand square degrees on the sky, and thereby unravel the mystery of dark energy and the expansion of the universe.

Mapping dark matter over a wide region is key to understanding the properties of dark energy, which controls the expansion of the universe.

To get a sufficient amount of data, astronomers need to observe galaxies more than a billion light-years away, across an area greater than a thousand square degrees.